Acne vulgaris is a self-limiting skin disorder seen primarily in adolescent.Tumour necrosis factor α (TNF α) in addition to being cytotixic for certain tumour cells turned out as a multifunctional cytokine that is involved in regulation of immunity and inflammation.The subject of this study include fifty patients with acne .twenty patients with papulopstular acne, twenty patients with nodulocystic acne and ten as healthy controls.All patients and control will be subjected to clinical evaluation and detection of TNF- α by molecular biological technique polymerase chain reaction (PCR).